1. Field of the Invention
The present invention relates to an automatic vehicle following control system which comprises a leading vehicle driven by a driver and a platoon of following vehicles running in follow mode to the leading vehicle.
2. Description of the Related Art
In recent years, there have been proposed automatic vehicle following control systems for controlling a platoon of unattended following vehicles to automatically run in follow mode to an attended leading vehicle driven by a driver. The proposed automatic vehicle following control systems are effective to make the following vehicles free of any human drivers.
One known automatic vehicle following control system is disclosed in Japanese laid-open patent publication No. 5-170008, for example. According to the disclosed automatic vehicle following control system, the leading vehicle transmits information as to its manipulated variables, such as a steered quantity, a throttle valve opening, etc. and its running status variables such as a vehicle speed, a vehicle acceleration, etc. to the following vehicles, and each of the following vehicles controls its own manipulative variables and an engine control variable thereof in a feed-forward control mode to follow the leading vehicle along the same trajectory as the leading vehicle, based on the transmitted manipulated and running status variables of the leading vehicle and the running status variables of the following vehicle.
Another known automatic vehicle following control system is revealed in Japanese laid-open patent publication No. 10-172099. The revealed automatic vehicle following control system determines a predicted position of a following vehicle after a predicted period of time, calculates a lateral error or deviation of the predicted position from the trajectory of a leading vehicle, and controls the direction of travel of the following vehicle in order to reduce the calculated lateral error.
In the above known automatic follow-mode vehicle control systems, it is presupposed that the following vehicles are capable of running in follow mode to the leading vehicle without fail, and care is taken to avoid intra-platoon collisions such as a collision between the leading vehicle and the following vehicles and a collision between the following vehicles.
However, the conventional automatic follow-mode vehicle control systems do not take into account any vehicle follow-up control details in the event of a malfunction of either one of the following vehicles in the platoon.